Protective or hazardous duty garments are widely used in various industries to protect the wearer from various hazardous conditions such as heat, smoke, cold, sharp objects, chemicals, liquids, fumes and the like. The protective garment may include an outer shell layer, a thermal barrier or thermal liner located inside the outer shell, and a moisture barrier located inside the outer shell. The moisture barrier may be made of semi-permeable material such that the moisture barrier is generally liquid impermeable and generally moisture vapor permeable.
The moisture barrier may be located inside the outer shell to block moisture from the ambient environment from passing through the garment, while allowing moisture vapor inside the garment to pass through the moisture barrier. However, although the moisture barrier may be generally permeable to moisture vapor to allow moisture vapor to pass therethrough, moisture vapor may still remain trapped inside the garment. In particular, under heavy work conditions the moisture vapor generated by the wearer (for example, by perspiration) may be generated at a rate greater than that which can pass through the moisture barrier.
In addition, wearers of protective garments may often carry heavy equipment, such as a self-contained breathing apparatus (“SCBA”) tank or the like. Such equipment may be carried on the user's back, which can compress the garment and reduce its thermal protection at such areas of compression.